URGENT issue: pg-xlog growing on master!

Hi, My pg_xlog dir has been growing rapidly the last 4 days, and my disk is now almost full (1000Gb) even though the
databaseis only 50Gb. I have a streaming replication server running, and in the log of the slave it says: 

cp: cannot stat `/var/lib/postgresql/9.2/wals/0000000200000E1B000000A9': No such file or directory
cp: cannot stat `/var/lib/postgresql/9.2/wals/0000000200000E1B000000A9': No such file or directory
2013-06-10 11:21:45 GMT FATAL:  could not connect to the primary server: could not connect to server: No route to host
        Is the server running on host "192.168.0.4" and accepting
        TCP/IP connections on port 5432?

All the time.

I have tried to restart the server, but that didn't help. I checked the master, and the file
/var/lib/postgresql/9.2/wals/0000000200000E1B000000A9does not exist! I'm pretty lost here, can someone help me solve
thisand get my master server cleaned up. What is causing this, and what do I need to do? 

Kind regards